Fun
facts on numbers (and their strange properties), both mathematical
and cultural, tantalising problems and anecdotes. The number
facts in this website are also available as features for
print and electronic publishing.

You
can now purchase “Numberopedia: What's Special
About This Number” by G. Sarcone in pdf
format! 189 pages filled with an incredible variety
of fun facts on numbers (and their peculiar properties),
both mathematical and cultural, tantalizing problems and
anecdotes. There is much to learn for everyone!
After confirmation of your order, we will email you the code
to access the corresponding download page

Select
any prime
number equal or greater than 5, square it, subtract 1 from
that, then the result is always divisible by 24. For instance, 372 -
1 = 1368 is divisible by 24. However, this works just
as well with any odd
number not divisible by 3. For instance, 1252 -
1 = 15624 is divisible by 24. In fact, any number of the
form p2 - q2 can be divisible
by 24, for p and q primes > 3.

The
product of 4 consecutive numbers n(n+1)(n+2)(n+3)
is divisible by 24.

24
is the largest number of Knights you can place on a chessboard
such that none of them can capture any other using the standard
chess Knight's moves.

The Slinky
toy (aka "Lazy Spring") is a toy consisting of
a 24-meter (18-foot) long coil spring that
stretches and can bounce up and down.

The 25th
Hour is a 2002 Spike Lee urban drama based on David
Benioff's novel.

A "pony" is
a British slang for £25.

A chiastic saying: "The
two greatest highway menaces are drivers under 25 going
over 65 and drivers over 65 going under 25".

26

is
the only number sandwiched between a square (52)
and a cube (33).
is the difference of the second pair of amicable
numbers:
1210 - 1184 = 26
is the smallest number which is not a palindrome, but has a square
which is: 262 = 676
is the sum of the following series (J. Bernoulli):

∞∑1

n3

2n

The
26 letters of the alphabet can make 40,329x1022 different
combinations.

"God's
Number" is the minimum number of moves needed to solve any
disordered Rubik's
cube. It is so named because God would only need the smallest
number of moves to solve a cube! The research has proved that
God's number is 26. Nevertheless, theoretical
work suggests that God's Number could be in the 'low 20s'.

26
has also a special divine significance in Gematria because
it is the sum of the letter-values of the 'Tetragrammaton',
the Hebrew biblical name of God ( יהוה Yahweh):
Yod + Heh + Wau + Heh = 10 + 5 + 6 + 5 = 26
The diagram above shows the 'Tetragrammaton' written in Phoenician
(blue script), Aramaic (red script) and modern Hebrew (black script).

is
the first odd or masculine cube (odd numbers
were considered masculine by the Pythagoreans; even numbers feminine...
Because they were supposed to be weaker than the odd: in fact
odd + even always give odd, and two evens can never produce an
odd, while two odds produce an even).

is the
number of integer partitions of 15 into distinct parts.

is the
smallest 2-digit number in which the sum of digits is equal to
the sum of prime factors, e.g.:
27 = 3 x 3 x 3 and 2 + 7 = 3 + 3 + 3 = 9
is the smallest integer which is the sum of 3 squares in two different
ways:
12 + 12 + 52 = 27 and 32 +
32 + 32 = 27

The 27th
hexagram of the I-Ching reveals:THE JUDGMENT
THE CORNERS OF THE MOUTH.
Perseverance brings good fortune.
Pay heed to the providing of nourishment and to what a man seeks
to fill his own mouth with.

is
the number of bones in the human hand.
is the number of "cubies" in a Rubik's cube.

The
numbers of atoms in the body of an average male (80 kg, 175 lb)
is about 1027.

The
musician/humorist 'Weird
Al' Yankovic often includes the number 27 somewhere in his
songs, videos, album art, and memorabilia. For example, he wears
a 27 on the cover of the Running with Scissors album,
and 27 photos are included in the photo gallery on the 'Weird
Al' Yankovic Live! DVD. This trademark began as several
coincidental appearances of the number, but Yankovic began intentionally
using it after the original incidents were pointed out to him.

The
Twenty-Seven Club: Kurt Cobain, Jimi
Hendrix, Janis Joplin and Jim Morrison all died at age
27.

The
importance of number 27 in Roman rituals
In 17 AD, to celebrate the Secular Games, the emperor
Augustus commissioned a hymn ('Carmen
Saeculare') from the poet Horace which was sung by twenty-seven
boys and twenty-seven girls.
Every March 16th and 17th, a solemn procession made a circuit of
twenty-seven chapels called "Argei" located
in various parts of the city of Rome.

The
27-letter word sovramagnificentissimamente ('in a very
very very magnificent way'), used by Dante in "De vulgari
eloquentia" in the 14th century, was one of the longest
words in the Italian language. More info on "A
collection of word oddities and trivia".

The "Twenty
Eight" parrot is an Australian bird, so named because
it sounds like the words "28" when it calls.

Recycling:
even an old calendar becomes new again every 28 years!

29

successive
primes up to 29 are separated at most by 3 integers (the mean
gap being 2).
is the smallest prime of the form 7n + 1.
is the 7thLucas
number.
is a Perrin
number. In mathematics, the Perrin sequence is defined by the
recurrence relation: P(0) = 3, P(1) = 0, P(2) = 2;
and P(n) = P(n - 2) + P(n - 3), for
n > 2.
is the 3rd number n (following 1 and 5) such that 2n2 -
1 is a square, in fact: 2 x 292 - 1 = 412--
Source: 'Dictionary
of Curious and Interesting Numbers' by David Wells
is a Markov
number, it appears several times in the Markov triples: (2,
5, 29), (2, 29, 169), (5, 29,
433), (29, 169, 14701)... that define the solutions
to the Diophantine
equation:
x2 + y2 +
z2 = 3xyz
is the exponent of the largest power of 2 whose digits are all
distinct: 229 = 536 870 91
is the last term of the only sexy
prime quintuplet:
5, 11, 17, 23, 29is
the smallest multidigit prime whose product of digits of its cube
is also a cube:
293 = 24389 and 2 x 4 x 3 x 8 x 9 = 1728 = 123

A pizza
can be divided into 29 pieces with just 7 straight
cuts.

No sum
of three 4th powers is divisible by either 5 or 29 unless
they all are. -- Euler

TWENTY
NINE is the only number written with as many strokes as its numerical
value.

The
probability of being born on 29th February is
1/1,461.Bob Morris wrote:
Is really 1/1,461 the probability of being born on February 29?
If leap
years occurred once every four years, it would be, but there
are a couple of additional rules for determining if a year is a
leap year. If it is divisible by 100, it is not a leap year, but
if it is divisible by 400, then it is a leap year (for example,
1900 was NOT a leap year because it is divisible by 100. The year
2000 IS a leap year because it is evenly divisible by 100 and by
400). This means that in any 400 year period, there are 365 x 400,
or 146,000, non-leap days. Leap days number 100 (one every four
years) - 4 (one every hundred years) + 1 (one every four hundred
years), so there are 97 leap days every 400 years.
The probability of being born on February 29 is therefore 97/146,097.

Leap
Year Checker
Is the year:
a leap year?
Answer:

29.783
km/s is the average orbital speed of the Earth around the Sun.

29.53
days is the amount of time for the Moon to complete one orbit
around the Earth (synodic
month).

The
planet Saturn requires over 29 years to orbit
the Sun (solar revolution).

is
the number of bones in a normal human skull.
is the number of days February has on leap years.

In
numerology, 29 is a very unlucky number and indicates uncertainties,
treachery and deception from others. It also stands for dangers,
unreliable friends, grief and deception from the opposite sex.
In the Tarot, the 29 is represented by the 3 of Wands. It infers
spiritual power, introspection, reflection and receptivity.

30

is
a pyramidal number - the sum of the first 4 square numbers:
12 + 22 + 32 + 42
is the largest number such that every smaller coprime to
it is prime.

11 +
22 + 33 ... + 2828 + 2929 +
3030 is prime!- Crespi de Valldaura

= 4
+ 5 + 6 + 7 + 8
≈ π3 - π/500

30 + 25 =
55 and 55 x 55 = 3025

n5 – n is
divisible by 30.

A
polygon with 30 sides is called a tricontagon. Both
an icosahedron and a dodecahedron have 30 edges.

Used
to indicate the end of a wire service story (possibly a corruption
of German fertig - "finished, ready" or in
journalistic context "end of story"?).

Emile
Coué, a physician who formulated the Laws
of Suggestion, was known for encouraging his patients to
say to themselves 30 times a night before
going to sleep: "Everyday in every way, I am getting better
and better".

31
331
3331
33331
333331
3333331
33333331 are all primesBut
will there emerge a composite number?
333333331, the 8th term of the sequence, is not prime; it is divisible
by 17. What’s more, in this sequence every 15th number is
divisible by 31. In fact, any sequence that looks like ab, abb, abbb, abbbb, … (where a and b are
digits) contains terms that are periodically divisible by the first
2-digit number ab.
The lesson to be learnt is: you can never assume that statements
that hold for small numbers will hold for big numbers!

A
billion (1,000,000,000) seconds is 31 years.

Strangely
enough, the French expression "être sur son trente-et-un
(31)" means 'to be dressed to the nines' in English, and "anar
de vint-i-un (21) botó" in Catalan.

33
Bits of Entropy
There are 6.6 billion people in the world. So in order to figure
out who you are you only need 33 bits of data about you or any
person. More
info.

In the
ASCII code, 33 represents an exclamation mark.

L33t (sometimes
rendered LEET, 1337, or 31337)
is an alphabet used primarily on the Internet, which uses various
combinations of ASCII characters to replace Latinate letters.
It was initially developed as an exclusionary language: a way
to encode text so that messages could only be read by the initiated...
Example sentence: L337 15 n07 4 c0mm0n 1n73rn37 5p34k 4m0n9
r34l h4x0r. English rendering: 'Leet is not a common internet
speak among real hackers'.

33 is
a significant number in modern numerology, as it is one of the
master numbers along with 11 and 22.

is the
word a Romance
language speaking patient is usually asked to say when a
doctor is listening to his/her lungs with a stethoscope (fr: trente-trois,
it: trentatrè, ro: treizeci şi trei,
sp: treinta y tres, and por: trinta e três).
In fact, the sound TRR...TRR... makes the lungs vibrate
making easier to detect a possible respiratory anomaly.

In Spanish,
is the smile-to-the-camera word, as is 'cheese' in English. "Diga
treinta y tres" ('say thirty-three') is the same
as 'say cheese'.

34

is
a Fibonacci and an heptagonal
number.
is the smallest number which can be expressed as the sum of two
primes in four ways, and also the smallest number to be surrounded
by numbers with the same number of divisors (4):
33 = 3 x 11; 34 = 2 x 17; 35 = 5 x 7

is
the smallest number which is the sum of pairs of distinct odd
primes in four ways:
36 = 5 + 31 = 7 + 29 = 13 + 23 = 17 + 19
is the smallest integer (besides 1) being both a square and
a triangular number.
is the smallest number to have 9 different factors: 1, 2, 3, 4,
6, 9, 12, 18, and 36.

In our
Millenium occur 36
palindromic dates in the mm-dd-yyyy format. Palindromic
dates are the same when read backward and forward; the first
ones are:
10/02/2001, 01/02/2010, 11/02/2011, 02/02/2020, etc.

The 36
officers problem is a puzzle proposed by Swiss mathemacian
Leonhard Euler in 1782. The problem asks if it is possible
to arrange six regiments consisting of six officers each of
different ranks in a 6x6 square so that no rank or regiment
will be repeated in any row or column. Such an arrangement
would form a Graeco-Latin square. The answer is that no such
arrangement is possible...

36
Hidden Holy Persons (Heb. ל״ו צַדִּיקִים, "36
righteous men")
In the Kaballah, the numerical value of the Hebrew letters lamed (L)
+ vav (V) is 36, and represents the 36 hidden
tzaddikim -wise men- whose actions helped to repair the
world. The concept of the "Hidden
Tzaddikim" goes back to the early days of Chassidism,
in the 17th century. According to Jewish folklore these 'hidden
saints', called in Yiddish Lamedvavniks, were responsible
for the fate of the world and one of them is considered to be the
Messiah.

Chinese
characters can range in complexity from just one horizontal stroke — yi “one” to
36 strokes, the largest number of strokes in any character actually
used: is contained in the word nàng referring
to “the sound your voice makes through a stuffed up
nose”.

37

is
a hexagonal number because it can be arranged in a pattern of
nested hexagons: 37 = 1 + 6 + 12 + 18.
is the maximum number of 5th powers needed to sum to any integer
(Hilbert-Waring's problem).

If you
ask someone to think of any number from 1 to 50, one people
out of three answers 37. Strangely, if you
ask someone else to think of any number from 1 to 5, the probability
that he/she will answer 3 is one out of three;
and if you ask to think of any number from 5 to 10 instead, the
probability that he/she will answer 7 is also one
out of three! -- G. Sarcone

is a
'psychologically random number' - that is a number which is chosen
more often when someone is asked to pick a number (usually this
kind of number is odd and doesn't end in 5, because there is
a natural psychological bias to think of even numbers and numbers
that end in 5 are 'less random'). 37 appears disproportionately
in television and movies.

On a
calculator, any row, column or diagonal typed forwards and then
backwards is divisible by 37. For example:
147741 divided by 37 = 3993
852258 divided by 37 = 23034
753357 divided by 37 = 20361- Posted by Tim Barss -

A 6-digit
number in which the first 3 digits are consecutively-increasing
numbers; and the last 3 digits, consecutively-decreasing numbers,
is divisible by 37. For instance, the numbers 123987, 234765
and 567543 are all divisible by 37.

is
the last Roman
numeral when written lexicographically (XXXVIII).
is the largest known even number which can be represented as sum
of two distinct primes in only one way: 38 = 31 + 7
is the sum of the squares of the first three primes:
38 = 22 + 32 + 52

37 and
38 are the first pair of consecutive positive integers not divisible
by any of their digits (the second one being 46 and 47...).

It
needs approximately 40 grams of petrol to manufacture
1 kg of strawberry yogurt. The so-called ‘environmental’ products
are not environmental at all if the distances covered by freight
transports are included!

Symbolizes
the number of trial and privation, possibly starting when the
Babylonians observed the forty-day disappearance of the Pleiades (aka 7
Sisters) which coincided with the rainy season, storms and
floods, trial, danger. The Pleiades' return marked the start
of the New Year Festival. Other negative associations for forty
are:- 40 years of Hebrew wandering in the desert,
- 40 days and nights of the great flood,
- 40 days of Moses on Sinai,
- 40 days of Elijah's journey,
- 40 days of mourning for Jacob,
- 40 days of Lent, the period of fasting, self-denial, and penitence
traditionally observed by Christians in preparation for Easter,
- 40 day period of isolation in the Roman port, which survives
in the word quarantine.

But
in monotheistic religions, 40 may also be shorthand
for 'a long time'. In fact, Jesus spent 40 days fasting in the
wilderness; God gave Nineveh 40 days to repent; the great flood
lasted 40 days and 40 nights; the Jewish people wandered the
desert for 40 years. Imam al-Baqir has said: "The prayers
of someone who drinks wine are not accepted for 40 days."

WD-40 is
the trademark of a widely used penetrating oil spray. It was
developed in 1953 by the chimist, Norm Larsen to eliminate water
and prevent corrosion on electrical circuitry. WD-40 stands for
'Water Displacement, 40th attempt'. The name was coined by Norm
Larsen itself, while he was attempting to concoct the formula
to prevent corrosion by displacing water. Norm's persistence
paid off when he perfected the formula on his 40th try.

A
typical pregnancy actually lasts 40 weeks.

40 is
the number of thieves Ali Baba clashes with in "Arabian
Nights".

The
French expression "s'en ficher (moquer, foutre)
comme de l'an quarante" (literally 'not
to care like the year forty') means not to care, not
to give a damn. This expression is a distortion of an old
French saying "s'en moquer comme de l'Alcoran" (literally
'not to care like the coran', XVIIIth century).

is
a 'cult number', whose cult status originated with Douglas Adams'
use of 42 as 'The Answer' to the ultimate question of life, the
universe and everything in his "Hitchhiker's Guide to the
Galaxy" series.

is
the area of a scalene triangle having integer sides, with a=7, b=15
and c=20 (Heronian
triangle).

is the
5thCatalan
number. Catalan numbers are generated by the formula Cn =
[(2n)!/n!(n+1)!]

The
reciprocal of 42 is the smallest fraction in a sum of 4 fractions
to add up to 1: 1/2 + 1/3 + 1/7 + 1/42 = 1

The
expression n7 - n is divisible by
42.

The
expression xy + x + y can never equal 42.

A 'gravity
train' - also referred to as the 'Gravity Sled' or 'Gravity
Express' - is a theoretical means of transportation intended
to go between two points on the surface of a planet, following
a straight tunnel that goes directly from one point to the
other through the interior of the planet. All possible gravity
trains on a given planet would take exactly the same amount
of time to complete a journey (the length of a trip depends
only on the density of the planet and the gravitational constant).
For Earth, this time would approximatively equal 42 minutes.

is
the smallest prime that can grow 5 times by the right:43 is prime,439 is prime,4391 is prime,43913 is prime,439133 is prime,4391339 is prime.
...and the smallest prime that can grow 14 times by the left:443 is prime,
8443 is prime,
18443 is prime,
918443 is prime,
3918443 is prime,
53918443 is prime,
653918443 is prime,
7653918443 is prime,
27653918443 is prime,
427653918443 is prime,
3427653918443 is prime,
33427653918443 is prime,
933427653918443 is prime,
6933427653918443 is prime.

The
43th term of the Fibonacci's sequence is 433494437
and is prime!

43
is the 4th term of the Sylvester's
sequence:
2, 3, 7, 43, 1807, 3263443, 10650056950807, 113423713055421844361000443,
...
This sequence is generated by taking the product of the first n terms
and adding 1 (for instance: 2 x 3 x 7 + 1 = 43). Because of the
way each term is calculated, no two terms in the sequence have
a common factor. Then, no two terms have a common prime factor,
and thus there are an infinite number of primes!

Licor
43,
also known as "Cuarenta Y Tres" (meaning 'forty-three'
in Spanish), is a liquor made in Spain for over a thousand
years dating back to the time of the Carthaginians (?).
It is a bright yellow color liquor that has a sweet citrus-vanilla
flavor. 'Licor 43' derives its name from the fact that
it is a mixture of 43 basic elements, principally fruit
and fragant herbs.

The
number 43 symbolically represents the principle of deliverance
or change.

The
sum of the first 9 digits placed in increasing or decreasing
order, 123456789 and 987654321, gives obviously 45. And the difference
between these two numbers gives a result of nine digits, 864197532,
of which the sum of each one gives also 45.

is
a cult number; some people claim that the number forty-seven
occurs in nature with noticeably higher frequency than other
natural numbers.
is the number of samurai involved in the famous historical Ako
vendetta; sometimes referred to as the '47 Ronin'.
The number 47 mysteriously appears in many episodes of Star Trek:
'The Next Generation', 'Voyager', and 'Deep Space Nine'.

A
person uses approximately fifty-seven sheets of toilet paper
each day.

is
the smallest number with 10 proper divisors. Actually, 48
= 24 x 3 and thus is divisible by 2, 3, 4,
6, 8, 12, 16, and 24.
is also the smallest even number that can be expressed as a sum
of two primes in 5 different ways:
5 + 43, 7 + 41, 11 + 37, 17 + 31, and 19 + 29
is the double factorial of 6, four dozens, a 17-gonal number, and
a Harshad
number.
is an arc-cotangent
irreducible number, that is a positive integer n for
which the greatest prime factor of n2 + 1 meets
or exceeds 2n: 482 + 1 = 5 x 461 and 461 > 2
x 48
The product of all 10 divisors of 48 equals 484.

is a
repeating decimal with a period of 42:
1⁄49 = 0.0204081632 6530612244 8979591836 7346938775 51 (42
repeating digits)
The first 10 decimals of 1/49 represent successive powers of 2:
0,0204081632...

is
a pentagonal number as well as a centered pentagonal number (one
of the few numbers to be both) and an 18-gonal number.

is the
smallest number which can be written with all the digits from
1 to 5 (without repetition) as a sum of prime numbers:
2 + 3 + 5 + 41

A
scalene triangle having sides 51, 52 and 53
(consecutive integers) has an area that is also an integer (1170
units2). Such triangles whose
sidelengths and area are all integers are called Heronian
triangles.

There
are 51 and 3/7 degrees in the angle of the Egyptian
pyramids, which is 1/7 the arc length of a circle.

is
the 5thBell
number (Bell numbers is the number of distinct possible ways
of putting n distinguishable balls into one or more
indistinguishable boxes).
is a decagonal
number (4 x 42 - 3 x 4).
is a centered 17-gonal number.
is the 3rduntouchable
number (an untouchable number is a positive integer that cannot
be expressed as the sum of all the proper divisors of any positive
integer, including the untouchable number itself).

'Genjiko'
is the name of a popular Japanese design whereby five vertical
bars are either connected or non-connected at the top resulting
in 52 design combinations (see picture opposite).
Its name originates from a traditional Japanese game in which 5
incense sticks are randomly taken out from a bag containing 25
incense sticks (5 bags x 5 different types of incenses) and are
lit one after another. The player draws 5 vertical lines on a piece
of paper and adds a horizontal bar on the top section of the vertical
lines each time they smell the same scent.

The microcentury is 52 minutes
and 35.76 seconds and was introduced by Enrico
Fermi as the "standard" duration of a lecture period.
It's equal to exactly 3155.76 seconds, as one millionth
of the scientific Julian century, which is defined to be equal
to 36525 days of 86400 seconds each.

is the
number of weeks in a year.
is the number of cards in a standard pack without jockers
is the number of white keys on the piano (notes in C major scale).
is a significant number in the Maya calendar.

Patolli (or
Patole, Spanish form) is an Aztec board game utilizing 52
squares arranged in a cross form. Its name came from
the Aztec word for bean - patolli, meaning fava or kidney
bean.

52nd Verse
of Buddha's Dhammapada:
On FlowersLike a beautiful flower, brightly coloured and scented,
even so useful is the well-uttered speech of one who acts accordingly.-- Buddha (240 B.C.)

53

is
the smallest prime which is not the difference between powers
of 2 and 3.
is the only two-digit number that is reversed in hexadecimal (base
16): 3516

xy +
x + y never yelds 53.

the
reciprocal of 53 (1/53) has 13 digits that repeat:
0.01886792452830188679245283....

is the
sum of five consecutive primes: 5 + 7 + 11 + 13 + 17

the
sum of the first 53 integers is 1431, which
is divisible by 53, a property shared by many other numbers.

the
sum of the first 53 primes is 5830, which is
divisible by 53, a property shared by few other numbers.

the
sum of all consecutive prime numbers from 7 to 53 is the product
of 7 x 53:
7 x 53 = 7+11+13+17+19+23+29+31+37+41+43+47+53 = 371

The
reciprocal of 55 has a curious relationship to the Fibonacci
sequence: 1/55 = F(n)
x 8-(n+1) = 0.0181818182

Every
integer greater than 55 is the sum of distinct primes of the
form 4n + 3.

55 multiplied
by any of the odd numbers comprised between 90 and 110 produces
a palindrome numeral.

A
classic coin puzzle involving number 55
There are 10 hats containing each 17 coins.
9 hats contain "identical real" coins - weighing 10 grams
each.
But 1 hat contains 17 "identical" fake coins. Fake coins
are 1 gram off (so all 17 coins are either heavier or lighter).
All 170 coins are identical in every other characteristics. Your
mission is to locate the "fake" coins by using an electronic
balance once!Solution
Take just 1 coin from the hat #1; 2 from hat #2; 3 from hat #3,
and so on... In order to get:
1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55 coins.
Then measure the mass of the 55 coins. Obviously, if ALL the coins
were real the mass would be: 10 x 55 = 550 grams.
Now, if the actual mass is off by 1 gram, then the fake coins are
in hat #1. If by 2 grams, hat #2; by 3 grams, hat #3... In fact,
the difference in grams between 550 and the actual weighing gives
the rank of the hat containing the fake coins.

The "7-38-55 rule" states
that ommunication is 7% verbal, 38% tone of voice, and 55%
body language.

The
55th wedding anniversary is traditionally named "Emerald
Anniversary".

57 is
the number of sauce varieties H. Heinz lied about to promote
his famous ketchup (when he began his business, he actually had
many fewer than 57 sauces or food products!). The Heinz people
are still quite attached to the number 57: the phone number at
corporate headquarters in Pittsburgh is 237-5757, and the address
is P.O. Box 57. "Heinz 57" is also used as a joke slang
term for mixed-breed dogs, as well as people who are multiracial,
or most commonly, people who are of different national heritages.

The
most complex Chinese
character still in use is the sinograph 'biáng', with 57 strokes!
Which refers to Biang biang noodles, a type of noodle
from China's Shaanxi province.

is
a 'hoax
number', that is a composite number the sum of whose
digits is the sum of the digits of its distinct prime factors.
In this case:
5 + 8 = 2 + (2 + 9) -- prime factors of 58 being 2 and 29
58 reversed (85) is also a hoax number, in fact:
8 + 5 = 5 + (1 + 7) -- prime factors of 85 being 5 and 17

58° Celsius
is the highest air temperature ever recorded on earth (recorded
in Lybia, 1922).

The
Welsh name for a village on Anglesey Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch (also
spelt Llanfair Pwllgwyngyll and commonly known as Llanfair
PG) has 58 letters.

59

is
the smallest number which when divided by 2, 3, 4, 5, and 6 leaves
remainders of 1, 2, 3, 4 and 5, respectively.is
a "safe prime". That is, a prime of the form 2p +
1, where p is also a prime: 59 = 2 x 29 + 1

594 =
1334 + 1344 - 1584 (Euler argued
that there were solutions to the equation a4+ b4 = c4+ d4,
where a < c < d < b are
positive integers. The first solution is in fact a =
59)

59
inches = 1 yard + 1 foot + 11 inches

is
the number of times the minute and second hands on a clock are
aligned in one hour.

1
day on planet Mercury lasts about 59 Earth days.
Only 59% of the Moon's surface is directly visible from the Earth.

60

is
an abundant
number.
is adjacent to 2 prime numbers: 59 and 61.
is also an heptagonal
pyramidal number and a 21-gonal
number (icosihenagonal number of the form (19n2 -
17n)/2).
is the smallest number divisible by 1 through 6 and the smallest
number with 12 different divisors (1, 2, 3, 4, 5, 6, 10, 12, 15,
20, 30, 60).
is the smallest number which is the sum of two odd primes in 6
different ways: 60 = 29 + 31 (twin
primes) = 23 + 37 = 19 + 41 = 17 + 43 = 13 + 47 = 7
+ 53
is the product of Pythagorean
triples: 3 x 4 x 5

Base
60 was the number system used by the Mesopotamians and is the
reason we have 60 seconds in a minute, 60 minutes in an hour,
360 degrees in a circle, etc. - Posted by
Tim Barss

60 is
the last term of a sequence of increasing integers which can
be spelled in 5 letters: 3, 7, 8, 20 (score), 40, 50, 60 - G.
Sarcone

Each
internal angle in an equilateral triangle = 60 degrees.29 February (the leap day) is the 60th
day of the year.60 is the international telephone dialing code
for Malaysia.
‘Diamond wedding’ anniversary celebrates 60 years
of marriage.60 is the atomic number of Neodymium (Nd)
= 60 (60 protons and 60 electrons).
The cycle
of 60 in the Chinese zodiac (六十花甲;
liùshí huājiǎ) is formed by the 5 Elements
and 12 terrestrial Branches (Animals).

In our
Millenium occur 60
palindromic dates in the dd-mm-yyyy format. Palindromic
dates are the same when read backward and forward; the first
ones are:
10/02/2001, 20/02/2002, 01/02/2010, 11/02/2011, etc.

Did
the Ancient Greeks tell jokes? Yes, they did! Sources tell of
joke-groups; who met to trade and test their wit, like the Group
of Sixty who met in the temple of Heracles in Athens
in the 4th century BC, and whom even Philip of Macedon paid to
send him a collection of their best jokes (cf. Athenaeus, "Wise
Men At Dinner", 614d).

is
a cuban prime of
the form p = (x3 - y3)/(x - y),
where x = y + 1 and y > 0.
is a Pillai
prime, since 8! + 1 is divisible by 61, but
61 ≠ 1 + 8n, where n = any integer.
is the smallest prime whose reversal (16) is a square.
is the 6thEuler
number.
is a repfigit
number.

is
the smallest number with 7 divisors, and the smallest power of
2 with no prime neighbors.
is the square of 8, the cube of 4, and the 6th power of 2:
26 = 43 = 82 = 64is the difference of the first pair of amicable
numbers:
284 - 220 = 64
is the number of ways of distributing 7 identical objects into
one or more different containers.

There
are 64 squares on a checker/chess board.
In China, "64 incident" refers to the Tiananmen Square
protests which happened on 4 June 1989.

65

appears
in the Padovan
sequence, preceded by the terms 28, 37, 49 (it is the sum
of the first two of these).
is the lowest integer that becomes square if
its reverse is either added to or subtracted from it.
is the 'magic constant' of a 5x5 magic square.
The protein in egg whites coagulate at 65 degrees C (150 degrees
F).
In the ASCII code used by computers, 65 represents a capital letter
A.

The
last day of November
46 B.C. was the longest day in history, it lasted 68 days!

In May
'68 a general strike broke out across France. It quickly
began to reach near-revolutionary proportions before being
discouraged by the Stalinist oriented French Communist Party,
and finally suppressed by the government, which accused the
Communists of plotting against the Republic.

69

is
the fifth number that stays the same when written upside down
(such numbers are called strobogrammatic), the complete
list of invertable numbers starts: 11, 69, 88, 96, 101, 111,
181, 609, 619, 689, 808, 818, 888, 906, 916, 986, 1001, 1111,
1691, 1881, 1961, 6009, 6119...
As well as 6 and 9 being the same digit rotated 180 degrees, they
are also binary complements:
6 = 0110
9 = 1001

69 ≈ 163( - e) [...within
0.0005%]

has
the property that n2 and n3 all
together contain each digit once: 692 = 4,761 and
693 = 328,509

is often
the largest factorial that can be calculated by a pocket calculator:
69!≈1.71x1098 (less than 10100)

6932 =
6.96969696 · 1058

692 = 4761693 =
328509 (the two answers include all digits once)

The
title of the novel 69 by Ryu Murakami.
This number symbolizes also an erotic position... No need to describe
it!

You're
encouraged to expand and/or improve the number facts featured
on this page. Send
us your comments, feedback or suggestions.
You can use any of our content (pictures, texts) in your non-commercial
web page for free as long as you leave the copyright and author's info intact
and link to us. This
work is licensed under a Creative
Commons Attribution - NonCommercial - ShareAlike 2.5 License.

Source
credits
1. We always credit our sources, when we can.
2. Some of the material on this web section is submitted by our
readers/visitors. Where cited, excerpts are quoted or italicized,
and authorship credit is prominently supplied.
3. Most authors/submitters, however, prefer to remain anonymous,
for reasons of their own, and we respect their wishes.
4. If you believe you have identified material on this web site
that has not proper permission (and can provide us with verifiable
proof of ownership), or that should (but does not) credit a verifiable
source, please bring it to our
attention.
5. Any oversights, omissions and corrections will be updated as
soon as possible.